There are many insulated electrical cables for use in high temperature oil well, some of which are suitable for high pressure gassy oil wells. An example of such a cable is described and claimed in U.S. Pat. No. 4,096,351 granted to Robert V. Wargin and Clinton A Boyd on June 20, 1978.
Problems have arisen where the well fluid is very corrosive, as found, for example, in Mexico. In order to protect electrical cables in such wells, a jacket or sheath of lead is used over the insulated conductor. The life of these cables is relatively short because the jacket, not being exceptionally strong, becomes damaged and/or embrittled, especially when the cable is pulled during changes or replacement of the pumps.